Ramon van Handel wrote:
> >this means that the guest os driver needs the ability to allocate memory
> >and physically "lock" it. (can this be done in all OSes we intend to
> >support with plex86?)
>
> Yes. An OS that doesn't support that would also not support DMA transfers...
ah... ok :)
> >AND it ALSO means that starting with a specified amount of physical
> >memory, the memory "available" to other programs would ALWAYS be
> >dependant on the video memory requested... that doesn't seem like a
> >"good" plan to me (ie an 16Mb guest, selecting a 1024x768x32bit graphics
> >mode would allways have at most 12Mb available physical memory for
> >"other" purposes)
>
> But that's no problem; after all, you can specify in plex86.conf how much
> physical memory is allocated in total for the guest... what does it matter
> where the memory comes from ?
well, I imagine that if an "enduser" configures plex86 to have 16Mb
physical memory, he expects 16 Mb to be "available" and doesn't want to
be bothered with the fact that he "actually" will have 12 Mb available,
because our video driver allocates 4Mb physical memory
(and what if I need 8Mb in my video driver, or more??). I still think
this kind of memory should be allocated from the guests physical memory.
If the memory needed is large enough, people will be "mislead" by the
plex86 physical memory configuration item (at least, that's what I
believe).
> All memory is the same you know... (well, not completely true, but for this purpose
>it is ;))
well, that depends on how you look at it.. but *eventually* all guests
memory is the same I guess
> >as for the I/O ports, are there any specific ports "free" that can be
> >used for this purpose.
>
> Have a look at your favorite hardware reference and pick an interesting port.
> Any port above 0x1000 is usually free... but there are plenty free ones below
> there, too.
well, I was hoping we could establish an official "plex86 host<->guest
interface port". (every guest os specific device driver will need some
ports, so why not have plex86 manage a generic port that plugins can
register a callback for (IS it possible for multiple plugins to register
a callback on the SAME ports?) -> plex86 will take care of "parsing" the
packet data & passing information to a plugin callback.
--
Best regards,
Jeroen Janssen
+++
"Reflected-sound-of-underground-spirits?"
-- Economics explained
(Terry Pratchett, The Colour Of Magic)
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